Envelop



(No Model.)

A.'BUTZER.

ENVELOP.

No. 598,359. Pat ented' Feb. 1, 1898.

INVENTOI? /6?/. 16%

ATTORNEYS,

rm; "cams FzYERs coy, Pnofoumu, WASHINGTON. o -c NiTE TATES ALBERT BUTZER, or CARLYLE, ILLINoIs.

ENVELO P.

SPECIFICATION forming part of Letters Patent No. 598,359, dated February 1, 1898.

Application filed Tune 23, 1897. Serial No. 641,860. (No model.)

To aZZ whom it may concern:

Be it known that I, ALBERT BUTZER, of, Carlyle, in the county of Clinton and State of Illi- 1 nois, have invented a new and useful Improvement in Mailing-Envelops, of which the following is a full, clear, and exact description.

The object of my invention is to provide a safety mailing-envelop of exceedingly simple, durable, and economic construction and capable of being readily manipulated and which after having been once closed cannot be opened without mutilation and detection. A further object of the invention is to so construct the envelopthat without an excess of material being used the end portions of the envelop, which are usually the weakest portions, may be rendered much stronger than under the ordinary construction of envelops without detracting from the appearance of the. envelop or rendering the same in any manner bulky.

The invention consists in the novel construction and combination of the several parts, as will be hereinafter fully set forth, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a plan View of the blank from which the envelop is made. Fig. 2 is a rear elevation of the envelop folded with the sealing-fiap raised. Fig. 3 is a rear elevation of the envelopwith the sealing-flap closed. Fig. 4c is a horizontal section on the line 4 4 of Fig; 2. Fig. 5 is an inner face view of the keepervstrip, illustrating the manner in which the locking-tongue engages therewith to prevent the sealing-flap from being raised without detection after it has once been closed. Fig. 6 is a transverse section through the envelop,

I taken on the line 6 6 of Fig. 2. Fig; 7 is a section similar to Fig. 6, taken on a larger scale and illustrating the relation of the locking-tongue to the keeper-strip after the envelop has been scaled. Fig. 8 is an outer faceview of a portion of the locking tongue or strip; and Fig. 9 is a horizontal section taken through one end of the envelop, substantially on the line 9 9 of Fig. 3.

The blank from which the envelop is made consists of a front section or portion A, aback The front section and the back section are of substantially the same length, being represented as separated by the score-line 10, while a similar line 10 indicates the separation between the front section and the sealing-flap of the blank. A wing 11 is formed at each end of the front section A of the blank, represented as separated therefrom by score-lines'll, while narrower wings 12 are formed at the ends of the back section B, shown as separated therefrom by score-lines 12.

About centrally between the ends of the back section B of the blank a keeper-strip D, constituting an extension from the outer edge of the said section, is located, which outer edge is the upper edge of the back of the envelop when made up. The keeper-strip is of such length that when folded upon the inner face of the back section B it will extend practically to the bottom edge thereof, or where the back section connects with the front section. A series of longitudinal openings 13 is made in the keeper-strip, the material being only partially removed from the openings, the outer opening excepted, and the said material is bent inward and downward, as shown in Figs. 5, 6, and 7, forming a series of flaps 14, each flap being provided with a slot or an opening 14L where it is joined to the strip, the openings 14 being aboutcentrally between the side edges of the flaps.

A locking tongue or strip E is projected from the central portion of the outer or sealing edge of the sealingflap C. This tongue is provided with a series of cuts, so shaped as to form in the said tongue a series of pointed tabs 16, the cuts being indicated at 15, and the construction of the locking-tongue is best shown in Figs. 1 and 8. Each tab 16 is provided with gum or a like material (preferably something insoluble when dry) spread over its inner face, whereby as the gum or other applied material dries the tabs will incline inward at more or less of an angle to the body of the tongue, as shown in Fig. 8, in which the shaded lines indicate the extent to which the tabs incline from the body; The coated surfaces of the tabs are indicated by the reference-numeral 16 and are shown best in Figs. 1 and 2. The locking-tongue at its base is separated at its sides to a greater or less extent from the sealing-flap by means of cuts 17, and a line of slight perforations, or a score-line 18, defines the inner end of the tongue, rendering the tongue readily separable from the sealing-flap.

The sealing-flap is provided upon its inner face, at its front edge, with the usual coating 19 of mucilage, and mucilage is. likewise applied to what in the blank are the outer faces of the wings 12, carried by the back section of the blank, and what are actually the inner faces of the wings 11, carried by the front section of the blank, are covered by a coating 20 of some kind of insoluble cement or of bichromated glue, which after having been once exposed to strong light can never be steamed open or softened, always remaining hard.

In completing the envelop the wings 12 are bent inward on the score-lines 12 and their gummed surfaces brought in engagement with and secured to the inner face of the front section A when the front and back sections are folded one upon the other. Next the wings 11 of the front section of the envelop are carried over upon the outer face of the back section and attached thereto by the glue with which the said wings are covered. It will thus be observed that there is a double thickness at each end of the envelop, (clearly shown in Fig. 9,) rendering the ends of the envelop, which are usually considered the weakest points, reinforced and strengthened to a great extent, and this improvement is effected without adding to the labor in forming the envelop and without adding to the amount of material ordinarily used.

Before folding the back section upon the front section the keeper-strip, which is provided with a coating of glue 21 along its side edges, is bent over upon the inner face of the back section and secured thereto, forming a pocket d, (shown in Figs. 6 and 7,) the flaps 14: extending within the interior of the completed envelop. A slot 22 is also made in the back section B of the envelop near the point where the keeper-strip connects with said section. The fiaps 14 in the keeper-strip are so produced that said flaps will be a trifle lower than the corresponding tabs on the locking-tongue E,which is to enter the openings in said flaps, so that the tongue will have to be carried downward beyond the openings which the tabs of the tongue are to enter, the tabs of the said tongue entering the said openings only when the sealing-flap is in its normal position when the envelop is closed.

In operation the envelop having been made up and the contents of the envelop having been placed in position the sealing-flap is carried over the back of the envelop in the ordinary manner and the locking tongue is passed within the envelop within the slot 22 into the pocket d, and the sealing-flap is car ordinary closed position the pointed tabs of the locking-tongue will have been drawn up through the openings in the flaps of the keeper-strip, as shown in Fig. 5, thereby securely locking the tongue to the said strip, as shown in Fig. 7. Under this construction of the envelop no matter to what extent the envelop can be steamed it cannot be thus opened, and if opened by a knife or other sharp instrument the fact will be detected, and in. the event the sealing-flap is tampered with to such an extent that it may possibly become disengaged from the body 'it'will be impossible to open said sealing-flap, since the locking-tongue E will have such close engagement with the body of the envelop as to cause the tongue to become separated from the sealingflap before the latter can be opened.

Having thus described my invention, 1.

delicate connection with the blank, substantially as set forth.

2. In a mailing-envelop or like receptacle, a blank consisting of a front section, a back section and a flap-section, a keeper-strip projecting from the edge of the back section and formed with apertured flaps, the said back section being provided with a slot near the point Where the keeper-stri p connects therewith, and a locking-tongue projected from the sealing-flap of the envelop and provided with tabs adapted to enter the openings in the flaps of the keeper-strip, the said sealing-flap being provided with cuts at the sides of the lockingtongue extending into the body of the sealingfiap, substantially as shown and described.

3. In an envelop or like receptacle, a blank provided with an extension from one of its edges forming a keeper-strip, the said extension having openings made therein and apertured flaps extending from the wall of said openings, the said blank being also provided with a locking-tongue extending from the edge opposite that at which the keeper-strip is located, the locking-tongue being provided with tabs adapted to enter the openings in the flaps of the keeper-strip, the said lockingtongue at its base being separated at the sides from the body of the blank by cutsextending into the blank, the inner end of the tongue being defined by a score-line, whereby the tongue is readily separable from the blank, as and. for the purpose set forth.

4. In an envelop or like receptacle, a blank consisting of a front section, a back section and a flap-section, wings at the ends of the front and back sections, the wings of the front section being arranged to be carried over the IIO wings of the back section and to engage with said back section, a keeper-strip projecting from the back section and having a series of apertured flaps formed therein, the keeperstrip having cementing surfaces at its sides for engagement with the inner face of the back section of the completed envelop,to form a pocket,the back section being provided With a slot near the point Where the keeper-strip connects with said back section, the said slot leading into said pocket and a locking-tongue projecting from the flap-section of the envelop or receptacle and provided with tabs arranged to enter the openings in the flaps of the keeperstrip, the said locking-tongue at its base being separated at the sides by cuts from the sealing-flap, the inner ends of the cuts being united by a score-line defining the inner end of the tongue, as and for the purpose specified.

5. An envelop or like receptacle'provided with a back section having a slot therein near its edge and a pocket formedupon the inner face of the back section and communicating with saidslot the inner wall of said pocket being provided with flaps projecting into the interior of the envelop, each flap being formed with an aperture at its junction with the inner Wall of the pocket, and a locking-tongue projecting from the sealing flap of the envelop, said tongue being adapted to enter the said pocket through the slot in the back section, the said tongue being provided with tabs projecting beyond the plane of its inner face and adapted toenter the openings in the flaps of the said pocket, substantially as described. 6. An envelop or like receptacle having a pocket formed upon the inner face of the back section, the back section being formed with a slot opening into the said pocket, the pocketbeing provided WibhPIOjGCiDiOHS extending within the interior of the envelop and each pocket formed uponthe inner face of its back section, the said back section being formed with a slot opening into the said pocket, the inner Wall of said pocket being provided with projections extending within the interior of the envelop, and each provided with an aperture at the junction of the projection with the inner wall of the pocket, and a locking-strip projected from the sealing-flap of the envelop and arranged to enter the slot in the back section and extend into the said pocket, the said locking tongue or strip being provided with tabs adapted to enter the apertures in the proj ections from the pocket, the said sealing-flap being provided with cuts at the sides of the tongue extending into the body of the sealing-flap, the inner end of the tongue having a delicate connection with the sealing-flap, whereby the tongue is readily separable therefrom, the said pocket being formed by a strip forming an extension of the back section and folded upon and secured to the inner face of the said back section, substantially as set forth.

ALBERT BUTZER.

Witnesses:

MARY A. BROWN, JOHN DIETERICH. 

